public void testPropertiesFilesDefaultCombiningToResourceBundle() {
    final PsiFile file = myFixture.addFileToProject("prop_core_en.properties", "");
    final PsiFile file2 = myFixture.addFileToProject("prop_core_fi.properties", "");
    final PropertiesFile propertiesFile = PropertiesImplUtil.getPropertiesFile(file);
    final PropertiesFile propertiesFile2 = PropertiesImplUtil.getPropertiesFile(file2);
    assertNotNull(propertiesFile);
    assertNotNull(propertiesFile2);
    final ResourceBundle bundle = propertiesFile.getResourceBundle();
    final ResourceBundle bundle2 = propertiesFile2.getResourceBundle();
    assertTrue(bundle.equals(bundle2));
    assertSize(2, bundle.getPropertiesFiles());
    assertTrue(bundle.getDefaultPropertiesFile().equals(bundle2.getDefaultPropertiesFile()));
    assertEquals("prop_core", bundle.getBaseName());

    assertNotSame(
        propertiesFile.getLocale().getLanguage(), propertiesFile.getLocale().getDisplayLanguage());
    assertNotSame(
        propertiesFile2.getLocale().getLanguage(),
        propertiesFile2.getLocale().getDisplayLanguage());
  }